CN111538005A - SAR front-side-looking imaging method based on FPGA and multiple multi-core DSPs - Google Patents
SAR front-side-looking imaging method based on FPGA and multiple multi-core DSPs Download PDFInfo
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- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
- G01S13/88—Radar or analogous systems specially adapted for specific applications
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- G01S13/90—Radar or analogous systems specially adapted for specific applications for mapping or imaging using synthetic aperture techniques, e.g. synthetic aperture radar [SAR] techniques
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- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
- G01S13/88—Radar or analogous systems specially adapted for specific applications
- G01S13/89—Radar or analogous systems specially adapted for specific applications for mapping or imaging
- G01S13/90—Radar or analogous systems specially adapted for specific applications for mapping or imaging using synthetic aperture techniques, e.g. synthetic aperture radar [SAR] techniques
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- G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
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- G01S7/41—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00 using analysis of echo signal for target characterisation; Target signature; Target cross-section
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Abstract
The invention provides an SAR front side-looking imaging method based on an FPGA and a plurality of multi-core DSPs, which is used for solving the technical problem of poor imaging algorithm real-time performance existing in the existing high-speed aircraft SAR imaging platform and comprises the following implementation steps: 1. initializing a signal processor and SAR parameters; 2, the FPGA acquires and sends an echo signal matrix block; DSPn echo signal matrix blockPerforming distance dimension FFT interpolation; 4, DSPn is to echo signal matrix block after FFT interpolationCarrying out BP integral; DSPn vs { S1,S2,···,Sx,···,And performing sub-aperture image fusion.
Description
Technical Field
The invention belongs to the technical field of digital signal processing, relates to an SAR front-side-looking imaging method, in particular to an SAR front-side-looking imaging method based on an FPGA and a plurality of multi-core DSPs, and can be applied to the fields of rapid imaging processing of high-speed aircrafts and the like.
Background
Synthetic Aperture Radar (SAR) is the main body of Radar imaging, and has the widest application range. The synthetic aperture radar imaging technology obtains an SAR image with two-dimensional high resolution ratio of the distance dimension and the azimuth dimension by carrying out two-dimensional processing of the distance dimension and the azimuth dimension on a radar echo signal matrix, clearly shows the shape and the fine structure characteristics of a target, and greatly improves the detection and identification capability of the target.
In practical application, because a high-speed aircraft needs to have certain maneuverability to perform actions such as turning and turning, a radar is required to observe a target scene in advance, and thus an SAR imaging algorithm is required to work in a front side view mode, compared with a traditional front side view mode, the SAR imaging algorithm has the defects that the calculation amount is large, the imaging real-time performance is difficult to guarantee, and the application of the SAR imaging technology in the high-speed aircraft is limited. Existing SAR front-side view imaging algorithms can be divided into two categories: one is a frequency domain SAR imaging algorithm based on Fourier transform, and the other is a time domain SAR imaging algorithm based on pixel-by-pixel interpolation and coherent accumulation. However, most frequency domain SAR imaging algorithms approximate a target transmission function, and the approximation conditions in the imaging algorithms are sensitive to SAR parameters, which brings about severe space-variant errors in large-scene imaging, resulting in poor SAR image quality, thereby limiting the application range of the SAR imaging technology in high-speed aircrafts.
In order to solve the above problems, the current research situation is to use a frequency domain SAR imaging algorithm and control a scene range of SAR imaging. The method reduces the operation complexity of the SAR imaging algorithm and ensures the real-time performance of SAR imaging. However, the method is only suitable for the condition that the imaging scene range is not large, and under the condition that the imaging scene range is large, the operation complexity of the imaging method is increased, and the real-time performance of SAR imaging is reduced; on the other hand, a time domain SAR imaging algorithm is adopted, and the number of digital signal processing chips on the signal processor is increased. The time domain imaging algorithm has flexible observation geometry, high focusing precision and controllable image resolution, has higher parallelism, but has huge calculation complexity, and can effectively solve the problem of poor real-time performance of the time domain imaging algorithm caused by huge calculation complexity by increasing the number of digital signal processing chips on a signal processor. In the technical text for realizing the multi-core DSP parallel architecture named as the large squint time domain SAR imaging algorithm published in 2019 by Haohao, a processing method for realizing the large squint time domain SAR imaging algorithm by utilizing four multi-core DSPs and grouping pairwise and adopting a mode of in-group running water and inter-group ping-pong is disclosed. However, the disadvantages of this method are: firstly, the time domain SAR imaging algorithm adopted by the method realizes sub-aperture image fusion by utilizing a two-dimensional interpolation mode, so that the calculation complexity of the time domain SAR imaging algorithm is increased, the time for forming an SAR front side view image by the method needs 2058ms, and the problem of poor real-time performance of the time domain SAR imaging algorithm still exists. Secondly, the multi-core DSP parallel architecture designed by the method cannot fully utilize the signal processing capability of a multi-core DSP chip, uses more hardware resources and has larger power consumption of a signal processor.
Disclosure of Invention
The invention aims to provide an SAR front-side-looking imaging method based on an FPGA and a plurality of multi-core DSPs (digital signal processors) aiming at the defects in the technology, and is used for solving the technical problem of poor imaging algorithm real-time performance in the existing high-speed aircraft SAR imaging platform.
In order to achieve the purpose, the technical scheme adopted by the invention comprises the following steps:
(1) initializing a signal processor and SAR parameters:
initializing FPGA on signal processor to acquire SAR and send carrier frequency to target sceneIs fcThe echo sampling matrix generated by the linear frequency modulation signal is SM×N(ii) a Initializing g multi-core DSP chips arranged in parallel on the signal processor as { DSP1, DSP2, …, DSPn, …, DSPg }; the initialization includes a synthetic aperture length L, a sub-aperture length LsubAnd the pitch RsWherein M is a distance dimension sampling point number, N is an orientation dimension sampling point number, DSPn is the nth DSP chip containing Q cores, g is the number of the multi-core DSP chip, Q is not less than 8, g is not less than 3, N ∈ [1, g];
(2) The FPGA acquires an echo signal matrix block and sends the echo signal matrix block:
FPGA echo sampling matrix SM×NPerforming distance dimension pulse compression to obtain an echo signal matrix after the distance dimension pulse compressionAnd will beDividing the signal into g echo signal matrix blocks with the same number as that of the multi-core DSP chips according to the azimuth dimensionThen, the nth echo signal matrix block is processedSending the data to a corresponding DSPn memory, wherein gnIs composed ofP is distance dimension pulse compression;
DSPn matrix block of echo signalsDivision into Q echo signal matrix blocks according to azimuth dimensionAnd J is used as an interpolation multiple pair through a q-th kernelPerforming distance dimension FFT interpolation to obtain echo signal matrix block after distance dimension FFT interpolation Represents the q +1 th echo signal matrix block after the FFT interpolation of the distance dimension, wherein, gn(q+1)Is composed ofK is the number of distance dimension points after distance dimension FFT interpolation, K is M × J, I is FFT interpolation, Q ∈ {0,1, …, Q-1 };
(4) echo signal matrix block after DSPn distance dimension FFT interpolationBP integration was performed:
(4a) DSPn calculates SAR to any point target U (r, theta) in a unified polar coordinate system (r, theta) taking the synthetic aperture center of SAR as a pole and the track of SAR as a polar axisU,θU) Is measured at a distance R (D; r isU,θU) Wherein r and θ are the polar diameter and polar angle, respectively, rUThe pole diameter in (r, theta) of the target U is an arbitrary point, thetaUThe polar angle of the target U in (r, theta) is an arbitrary point, D is the polar diameter of SAR in (r, theta), D ∈ [ -L/2, L/2);
(4b) DSPn echo signal matrix block after FFT interpolation according to azimuth dimensionIs divided intoAn echo signal matrix blockAnd use of R (D; R)U,θU) To pairBP integral is carried out to obtain a low-resolution sub-aperture imageWherein the content of the first and second substances,for the x-th echo signal matrix block, gnxIs composed ofNumber of columns, SxFor the x-th low-resolution sub-aperture image,
(5a) DSPn according to the carrier frequency f of the chirp signalcSynthetic aperture length L, sub-aperture length LsubSlope distance RsCalculating SxTrue wave number spectrum center K ofxAnd through KxTo SxThe wave number spectrum center is corrected to obtain a low-resolution sub-aperture image after the wave number spectrum center is correctedSx' is the x-th low-resolution sub-aperture image after wave number spectrum center correction;
(5b) low resolution sub-aperture images with center correction of the DSPn versus wavenumber spectraIFFT is carried out in the azimuth dimension to obtainAmplitude-time domain sub-aperture image The x-th time domain sub-aperture image after wave number spectrum center correction is obtained, wherein T is a time domain;
(5c) DSPn pairAmplitude-time domain sub-aperture imageSuperposing in the azimuth dimension to obtain a full aperture wave number spectrum SAR image;
(5d) and the DSPn performs FFT on the full-aperture wave number spectrum SAR image in an azimuth dimension to obtain an SAR front side view image.
Compared with the prior art, the method has the following advantages:
1. according to the invention, through carrying out wave number spectrum center correction and azimuth dimension IFFT processing on a low-resolution sub-aperture image obtained after BP integration, and finally realizing sub-aperture image fusion through a sub-aperture image superposition method, compared with the prior art which adopts two-dimensional interpolation in a distance dimension and an azimuth dimension to realize sub-aperture image fusion, the imaging algorithm disclosed by the invention has the advantages that the calculation complexity is greatly reduced, the load and the expense of a multi-core DSP chip are reduced, the real-time performance of a time domain SAR imaging algorithm is greatly improved, and the time for forming an SAR front side view image only needs 789 ms.
2. When the echo data after the FFT interpolation is subjected to BP integration, the method for carrying out BP integration on the echo data by rows is adopted, and compared with the existing method for carrying out block BP integration on the echo data in the azimuth dimension, the method solves the problem that the BP integration must be operated in a DSP memory with lower calculation speed due to large echo data amount, so that fewer hardware resources are used, the real-time performance of an imaging algorithm can be ensured, and the power consumption of a signal processor is lower.
Drawings
FIG. 1 is a block diagram of a signal processor employed in the present invention;
FIG. 2 is a flow chart of an implementation of the present invention;
FIG. 3 is an echo sampling matrix S according to the present inventionM×NThe DSP chip data dividing schematic diagram;
fig. 4 is a SAR front side view image obtained by processing measured data according to the present invention.
Detailed Description
The invention is described in further detail below with reference to the following figures and specific examples:
referring to fig. 1, a signal processor adopted in the present invention includes one FPGA chip and three multi-core DSP chips, where the FPGA chip used in this embodiment is XC7VX485TFFG1927-2 produced by Xilinx corporation, the number of logic units of the chip reaches 485760, the number of DSP Slice reaches 2800, the number of available pins for a user is 700, and the number of high-speed serial transceivers is 56, so as to implement various high-speed serial bus protocols, and the DSP chip used in this embodiment is TMSC320C6678 produced by TI corporation, and 8 processor cores are integrated in the chip, the master frequency can reach up to 1.4GHz, and the multi-core processors are allowed to execute computation tasks at full speed in parallel;
referring to fig. 2, the present invention includes the steps of:
step 1) initializing a signal processor and SAR parameters:
initializing FPGA on signal processor to acquire SAR and send carrier frequency f to target scenecThe echo sampling matrix generated by the linear frequency modulation signal is SM×N(ii) a Initializing g multi-core DSP chips arranged in parallel on the signal processor as { DSP1, DSP2, …, DSPn, …, DSPg }; the initialization includes a synthetic aperture length L, a sub-aperture length LsubAnd the pitch RsWherein M is a distance dimension sampling point number, N is an orientation dimension sampling point number, DSPn is the nth DSP chip containing Q cores, g is the number of the multi-core DSP chip, Q is not less than 8, g is not less than 3, N ∈ [1, g];
In this embodiment, a signal processorThe FPGA acquires the echo sampling matrix S through the analog-to-digital conversion chip ADS5463M×NThe distance dimension sampling point number M is 1024, the azimuth dimension sampling point number N is 2048, the number g of the multi-core DSP chips is 3, and the number Q of the DSPn cores is 8;
step 2), the FPGA acquires an echo signal matrix block and sends the echo signal matrix block:
FPGA echo sampling matrix SM×NPerforming distance dimension pulse compression to obtain an echo signal matrix after the distance dimension pulse compressionAnd with reference to fig. 3 willAveragely dividing the signal into g echo signal matrix blocks with the number equal to that of the multi-core DSP chips according to the azimuth dimensionThen, the nth echo signal matrix block is processedSending the data to a corresponding DSPn memory, wherein gnIs composed ofP is distance dimension pulse compression;
in this embodiment, a high-speed serial data interface Rapid IO is adopted to send g divided echo signal matrix blocks to a corresponding DSPn memory, wherein a data transmission link of the high-speed serial data interface Rapid IO is configured in a 4x mode, the transmission rate of each link is 3.125Gb/s, and the DSPn memory refers to a DDR SDRAM chip connected with the DSPn and having a capacity of 2 Gb;
DSPn matrix block of echo signalsDivision into Q echo signal matrix blocks according to azimuth dimensionAnd J is used as an interpolation multiple pair through a q-th kernelPerforming distance dimension FFT interpolation to obtain echo signal matrix block after distance dimension FFT interpolation Represents the q +1 th echo signal matrix block after the FFT interpolation of the distance dimension, wherein, gn(q+1)Is composed ofIn the embodiment, Q cores of the DSPn acquire an echo signal matrix block corresponding to each core from a DDR SDRAM chip in an EDMA mode to a secondary cache for FFT interpolation, after the FFT interpolation is completed, the Q cores of the DSPn store the echo signal matrix block after the FFT interpolation in a DDR SDRAM chip in an EDMA mode, and an interpolation multiple J takes a value of 8;
step 4) DSPn echo signal matrix block after distance dimension FFT interpolationBP integration was performed:
step 4a) DSPn calculates SAR to any point target U (r, theta) in a unified polar coordinate system (r, theta) with the synthetic aperture center of SAR as a pole and the track of SAR as a polar axisU,θU) Is measured at a distance R (D; r isU,θU) The calculation formula is as follows:
wherein r and theta are the polar diameter and the polar angle, respectively, rUThe pole diameter in (r, theta) of the target U is an arbitrary point, thetaUThe polar angle of the target U in (R, theta) is an arbitrary point, D is the polar diameter of SAR in (R, theta), D ∈ [ -L/2, L/2), and in the embodiment, DSPn is the instantaneous distance R (D; R) to increase the running speed calculated by the imaging algorithmU,θU) The calculation of (2) is carried out in the second-level cache;
step 4b) DSPn is used for interpolating the echo signal matrix block after FFT according to the azimuth dimensionIs divided intoAn echo signal matrix blockAnd use of R (D; R)U,θU) To pairBP integral is carried out to obtain a low-resolution sub-aperture imageThe calculation formula is as follows:
wherein exp [. C]Is an exponential function with e as the base, j is an imaginary number, Krc4 pi/lambda is distance wave number center, lambda is linear frequency modulation signal carrier frequency fcCorresponding to the wavelength, dD is the differential of the variable D,for the x-th echo signal matrix block, gnxIs composed ofNumber of columns, SxFor the x-th low-resolution sub-aperture image,
in this embodiment, DSPn is an echo signal matrix blockDot-by-dot, column-by-column, with the exponential term exp jKrcR(D;rU,θU)]Multiplying and accumulating the calculation results of all the columns to obtain a low-resolution sub-aperture image Sx;
step 5a) DSPn according to the carrier frequency f of the chirp signalcSynthetic aperture length L, sub-aperture length LsubSlope distance RsCalculating SxTrue wave number spectrum center K ofxAnd through KxTo SxThe wave number spectrum center is corrected to obtain a low-resolution sub-aperture image after the wave number spectrum center is correctedSx' is the x-th low-resolution sub-aperture image after wave number spectrum center correction;
step 5a1) DSPn calculates SxTrue wavenumber spectrum center of (c):
step 5a2) DSPn will pass KxThe wave number spectrum center obtained by calculation corrects the phase HxAnd SxIs taken as the product of SxWave number spectrum center ofCorrecting the result, wherein:
step 5b) low resolution sub-aperture image with DSPn corrected for wave number spectral centerIFFT is carried out in the azimuth dimension to obtainAmplitude-time domain sub-aperture image The x-th time domain sub-aperture image after wave number spectrum center correction is obtained, wherein T is a time domain;
in this embodiment, the low resolution sub-aperture image S is processedxWhen IFFT is carried out in azimuth dimension, Q cores of DSPn carry out IFFT on data blocks corresponding to the cores line by line in parallel;
step 5c) DSPn pairsAmplitude-time domain sub-aperture imageSuperposing in the azimuth dimension to obtain a full aperture wave number spectrum SAR image;
step 5c1) randomly selecting one multi-core DSP chip in { DSP1, DSP2, …, DSPn, … and DSPg } as DSPaAnd the rest g-1 multi-core DSP chipsSend to the DSPaMemory, wherein, a ∈ [1, g];
In this embodiment, DSPaFor DSP2 on the signal processor, DSP1 and DSP3 pass high respectivelyOn-chip Hyperlink and PCIE serial data interfaceSending to DDR SDRAM on DSP 2;
step 5c2) DSPaSuperposing the time domain sub-aperture images in the memory of the SAR and the time domain sub-aperture images in the g-1 multi-core DSP chips in the azimuth dimension to obtain a full aperture wave number spectrum SAR image;
in this embodiment, DSPaEach core of the time domain sub-aperture image is overlapped line by line, and the overlapped part of the time domain sub-aperture image is 50 percent of the original time domain sub-aperture image;
and step 5d) the DSPn performs FFT on the full aperture wave number spectrum SAR image in an azimuth dimension to obtain an SAR front side view image, as shown in FIG. 4, FIG. 4 is a front side view image which is formed by processing actual measurement data of the radar and has a scene size of 5km multiplied by 5km, and the imaging effect is good.
The above description is only one embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the appended claims.
Claims (5)
1. An SAR front-side view imaging method based on an FPGA and a plurality of multi-core DSPs is characterized by comprising the following steps:
(1) initializing a signal processor and SAR parameters:
initializing FPGA on signal processor to acquire SAR and send carrier frequency f to target scenecThe echo sampling matrix generated by the linear frequency modulation signal is SM×N(ii) a Initializing g multi-core DSP chips arranged in parallel on the signal processor as { DSP1, DSP2, …, DSPn, …, DSPg }; the initialization includes a synthetic aperture length L, a sub-aperture length LsubAnd the pitch RsThe SAR parameter of (1); wherein M is the number of distance dimension sampling points, N is the number of azimuth dimension sampling points, and DSPn isThe nth DSP chip containing Q cores, Q is more than or equal to 8, g is more than or equal to 3, n ∈ [1, g];
(2) The FPGA acquires an echo signal matrix block and sends the echo signal matrix block:
FPGA echo sampling matrix SM×NPerforming distance dimension pulse compression to obtain an echo signal matrix after the distance dimension pulse compressionAnd will beDividing the signal into g echo signal matrix blocks with the same number as that of the multi-core DSP chips according to the azimuth dimensionThen, the nth echo signal matrix block is processedSending the data to a corresponding DSPn memory, wherein gnIs composed ofP is distance dimension pulse compression;
DSPn matrix block of echo signalsDivision into Q echo signal matrix blocks according to azimuth dimensionAnd J is used as an interpolation multiple pair through a q-th kernelPerforming distance dimension FFT interpolation to obtain echo signal matrix block after distance dimension FFT interpolationWherein the content of the first and second substances,representing the q +1 th echo signal matrix block, g, after distance dimension FFT interpolationn(q+1)Is composed ofK is the number of distance dimension points after distance dimension FFT interpolation, K is M × J, I is FFT interpolation, Q ∈ {0,1, …, Q-1 };
(4) echo signal matrix block after DSPn interpolation on distance dimension and distance dimension FFTBP integration was performed:
(4a) DSPn calculates SAR to any point target U (r, theta) in a unified polar coordinate system (r, theta) taking the synthetic aperture center of SAR as a pole and the track of SAR as a polar axisU,θU) Is measured at a distance R (D; r isU,θU) Wherein r and θ are the polar diameter and polar angle, respectively, rUThe pole diameter in (r, theta) of the target U is an arbitrary point, thetaUThe polar angle of the target U in (r, theta) is an arbitrary point, D is the polar diameter of SAR in (r, theta), D ∈ [ -L/2, L/2);
(4b) DSPn echo signal matrix block after FFT interpolation according to azimuth dimensionIs divided intoAn echo signal matrix blockAnd use of R (D; R)U,θU) To pairBP integral is carried out to obtain a low-resolution sub-aperture imageWherein the content of the first and second substances,for the x-th echo signal matrix block, gnxIs composed ofNumber of columns, SxFor the x-th low-resolution sub-aperture image,
(5a) DSPn according to the carrier frequency f of the chirp signalcSynthetic aperture length L, sub-aperture length LsubSlope distance RsCalculating SxTrue wave number spectrum center K ofxAnd through KxTo SxThe wave number spectrum center is corrected to obtain a low-resolution sub-aperture image after the wave number spectrum center is correctedSx' is the x-th low-resolution sub-aperture image after wave number spectrum center correction;
(5b) low resolution sub-aperture images with center correction of the DSPn versus wavenumber spectraIFFT is carried out in the azimuth dimension to obtainAmplitude-time domain sub-aperture image The x-th time domain sub-aperture image after wave number spectrum center correction is obtained, wherein T is a time domain;
(5c) DSPn pairAmplitude-time domain sub-aperture imageSuperposing in the azimuth dimension to obtain a full aperture wave number spectrum SAR image;
(5d) and the DSPn performs FFT on the full-aperture wave number spectrum SAR image in an azimuth dimension to obtain an SAR front side view image.
3. the SAR front-side view imaging method based on FPGA and multiple multi-core DSP of claim 1 characterized in that R (D; R) is utilized in step (4b)U,θU) To pairBP integral is carried out, and the calculation formula is as follows:
wherein exp [. C]Is an exponential function with e as the base, j is an imaginary number, Krc4 pi/lambda is distance wave number center, lambda is linear frequency modulation signal carrier frequency fcCorresponding to the wavelength, dD is the differential of the variable D.
4. The SAR front-side view imaging method based on FPGA and multiple multi-core DSP of claim 1, characterized in that, the pass K in step (5a)xTo SxThe wave number spectrum center of (2) is corrected, and the method comprises the following steps:
(5a1) DSPn calculates SxTrue wavenumber spectrum center of (c):
(5a2) DSPn will pass KxThe wave number spectrum center obtained by calculation corrects the phase HxAnd SxIs taken as the product of SxThe wave number spectrum center correction result of (1), wherein:
5. the SAR front-side view imaging method based on FPGA and multiple multi-core DSP of claim 1, characterized in that the pair in step (5c)Amplitude-time domain sub-aperture imageThe superposition is carried out in the direction dimension,the method comprises the following steps:
(5c1) randomly selecting one multi-core DSP chip in { DSP1, DSP2, …, DSPn, … and DSPg } as DSPaAnd the rest g-1 multi-core DSP chipsSend to the DSPaMemory, wherein, a ∈ [1, g];
(5c2)DSPaAnd superposing the time domain sub-aperture images in the memory of the SAR and the time domain sub-aperture images in the g-1 multi-core DSP chips in the azimuth dimension to obtain a full-aperture wave number spectrum SAR image.
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CN113156435A (en) * | 2021-02-08 | 2021-07-23 | 西安电子科技大学 | Missile-borne SAR front-side view time domain imaging method based on embedded GPU |
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CN113156435B (en) * | 2021-02-08 | 2023-09-15 | 西安电子科技大学 | Missile-borne SAR front side view time domain imaging method based on embedded GPU |
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